<div class="refentry"><a id="glUseProgram"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>glUseProgram — install a program object as part of current rendering state</p></div><div class="refsynopsisdiv"><h2>C Specification</h2><div class="funcsynopsis"><table class="funcprototype-table" style="cellspacing: 0; cellpadding: 0;"><tr><td><code class="funcdef">void <strong class="fsfunc">glUseProgram</strong>(</code></td><td>GLuint <var class="pdparam">program</var><code>)</code>;</td></tr></table><div class="funcprototype-spacer"> </div></div></div><div class="refsect1"><a id="parameters"></a><h2>Parameters</h2><div class="variablelist"><dl class="variablelist"><dt><span class="term"><em class="parameter"><code>program</code></em></span></dt><dd><p>Specifies the handle of the program object
		    whose executables are to be used as part of current
		    rendering state.</p></dd></dl></div></div><div class="refsect1"><a id="description"></a><h2>Description</h2><p><code class="function">glUseProgram</code> installs the program
	object specified by <em class="parameter"><code>program</code></em> as part of
	current rendering state. Executables for each stage are created in
	a program object by successfully attaching shader objects to it
	with
	<a class="citerefentry" href="glAttachShader"><span class="citerefentry"><span class="refentrytitle">glAttachShader</span></span></a>,
	successfully compiling the shader objects with
	<a class="citerefentry" href="glCompileShader"><span class="citerefentry"><span class="refentrytitle">glCompileShader</span></span></a>,
	and successfully linking the program object with
	<a class="citerefentry" href="glLinkProgram"><span class="citerefentry"><span class="refentrytitle">glLinkProgram</span></span></a>.
	</p><p>A program object will contain executables that will run
	on the vertex and fragment processors if it contains one shader
	object of type <code class="constant">GL_VERTEX_SHADER</code> and one shader
	object of type <code class="constant">GL_FRAGMENT_SHADER</code> that have both
	been successfully compiled and linked.</p><p>While a program object is in use, applications are free to
	modify attached shader objects, compile attached shader objects,
	attach shader objects, and detach or delete shader
	objects. None of these operations will affect the executables
	that are part of the current state. However, relinking the
	program object that is currently in use will install the program
	object as part of the current rendering state if the link
	operation was successful (see
	<a class="citerefentry" href="glLinkProgram"><span class="citerefentry"><span class="refentrytitle">glLinkProgram</span></span></a>
	). If the program object currently in use is relinked
	unsuccessfully, its link status will be set to
	<code class="constant">GL_FALSE</code>, but the executables and
	associated state will remain part of the current state until a
	subsequent call to <code class="function">glUseProgram</code> removes it
	from use. After it is removed from use, it cannot be made part
	of current state until it has been successfully relinked.</p><p>If <em class="parameter"><code>program</code></em> is 0, then the current
	rendering state refers to an invalid program object, and the
	results of vertex and fragment shader execution due to any
	<a class="citerefentry" href="glDrawArrays"><span class="citerefentry"><span class="refentrytitle">glDrawArrays</span></span></a> or
	<a class="citerefentry" href="glDrawElements"><span class="citerefentry"><span class="refentrytitle">glDrawElements</span></span></a>
	commands are undefined.</p></div><div class="refsect1"><a id="notes"></a><h2>Notes</h2><p>Like texture objects and buffer objects, the name space for
	program objects may be shared across a set of contexts, as long
	as the server sides of the contexts share the same address
	space. If the name space is shared across contexts, any attached
	objects and the data associated with those attached objects are
	shared as well.</p><p>Applications are responsible for providing the
	synchronization across API calls when objects are accessed from
	different execution threads.</p></div><div class="refsect1"><a id="errors"></a><h2>Errors</h2><p><code class="constant">GL_INVALID_VALUE</code> is generated if
	<em class="parameter"><code>program</code></em> is neither 0 nor a value
	generated by OpenGL.</p><p><code class="constant">GL_INVALID_OPERATION</code> is generated if
	<em class="parameter"><code>program</code></em> is not a program object.</p><p><code class="constant">GL_INVALID_OPERATION</code> is generated if
	<em class="parameter"><code>program</code></em> could not be made part of current
	state.</p></div><div class="refsect1"><a id="associatedgets"></a><h2>Associated Gets</h2><p><a class="citerefentry" href="glGet"><span class="citerefentry"><span class="refentrytitle">glGet</span></span></a>
	with the argument <code class="constant">GL_CURRENT_PROGRAM</code></p><p><a class="citerefentry" href="glGetActiveAttrib"><span class="citerefentry"><span class="refentrytitle">glGetActiveAttrib</span></span></a>
	with a valid program object and the index of an active attribute
	variable</p><p><a class="citerefentry" href="glGetActiveUniform"><span class="citerefentry"><span class="refentrytitle">glGetActiveUniform</span></span></a>
	with a valid program object and the index of an active uniform
	variable</p><p><a class="citerefentry" href="glGetAttachedShaders"><span class="citerefentry"><span class="refentrytitle">glGetAttachedShaders</span></span></a>
	with a valid program object</p><p><a class="citerefentry" href="glGetAttribLocation"><span class="citerefentry"><span class="refentrytitle">glGetAttribLocation</span></span></a>
	with a valid program object and the name of an attribute
	variable</p><p><a class="citerefentry" href="glGetProgramiv"><span class="citerefentry"><span class="refentrytitle">glGetProgramiv</span></span></a>
	with a valid program object and the parameter to be queried</p><p><a class="citerefentry" href="glGetProgramInfoLog"><span class="citerefentry"><span class="refentrytitle">glGetProgramInfoLog</span></span></a>
	with a valid program object</p><p><a class="citerefentry" href="glGetUniform"><span class="citerefentry"><span class="refentrytitle">glGetUniform</span></span></a>
	with a valid program object and the location of a uniform
	variable</p><p><a class="citerefentry" href="glGetUniformLocation"><span class="citerefentry"><span class="refentrytitle">glGetUniformLocation</span></span></a>
	with a valid program object and the name of a uniform
	variable</p><p><a class="citerefentry" href="glIsProgram"><span class="citerefentry"><span class="refentrytitle">glIsProgram</span></span></a></p></div>
        {$pipelinestall}{$examples}
        <div class="refsect1"><a id="seealso"></a><h2>See Also</h2><p><a class="citerefentry" href="glAttachShader"><span class="citerefentry"><span class="refentrytitle">glAttachShader</span></span></a>,
	<a class="citerefentry" href="glBindAttribLocation"><span class="citerefentry"><span class="refentrytitle">glBindAttribLocation</span></span></a>,
	<a class="citerefentry" href="glCompileShader"><span class="citerefentry"><span class="refentrytitle">glCompileShader</span></span></a>,
	<a class="citerefentry" href="glCreateProgram"><span class="citerefentry"><span class="refentrytitle">glCreateProgram</span></span></a>,
	<a class="citerefentry" href="glDeleteProgram"><span class="citerefentry"><span class="refentrytitle">glDeleteProgram</span></span></a>,
	<a class="citerefentry" href="glDetachShader"><span class="citerefentry"><span class="refentrytitle">glDetachShader</span></span></a>,
	<a class="citerefentry" href="glLinkProgram"><span class="citerefentry"><span class="refentrytitle">glLinkProgram</span></span></a>,
	<a class="citerefentry" href="glUniform"><span class="citerefentry"><span class="refentrytitle">glUniform</span></span></a>,
	<a class="citerefentry" href="glValidateProgram"><span class="citerefentry"><span class="refentrytitle">glValidateProgram</span></span></a>,
	<a class="citerefentry" href="glVertexAttrib"><span class="citerefentry"><span class="refentrytitle">glVertexAttrib</span></span></a></p></div><div class="refsect1"><div id="Copyright"><h2>Copyright</h2><p>
            Copyright © 2003-2005 3Dlabs Inc. Ltd.
            This material may be distributed subject to the terms and conditions set forth in
            the Open Publication License, v 1.0, 8 June 1999.
            <a class="ulink" href="https://opencontent.org/openpub/" target="_top">https://opencontent.org/openpub/</a>.
        </p></div></div></div>
